Heat exchanger



J. A. BALMER HEAT EXCHANGER we L W4.

2 Sheets-Sheet 2 Filed July 16, 1945 grwe/wbm JAME: A. BALMER mwg Patented June 21, 1949 UNITED STATES PATENT OFFICE 1 near sxcmmaaa Jamel A. Balmer, Worcester, Mass., assignor to Riley Stoker Corporation, Worcester, Man, a

corporation of Massachusetts I Application July 1c, 1945, Serial No. 805,804

20laims. (01.251424) This invention relates to heat exchangers. and more particularly to apparatus of the type having a group of spaced parallel tubes through which a fiuid flows in heat exchange relation with a secsirable, and the overall dimensions of the entire apparatus have been increased accordingly.

It is one object of the invention to provide a heat exchanger having a group of tubes of comparatively small diameter and closely spaced, the construction being such as to facilitate a substantially uniform distribution of fluid throughout the spaces between the tubes.

It is a further object of the invention to provide a highly efflcient tubular heat exchanger having a large heat transfer capacity in proportion to the space occupied.

with these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

Referring to the drawing illustrating one embodiment of the invention, and in which like reierence numerals indicate like parts,

Fig. 1 is a vertical sectional view through a heat exchanger;

Fig. 2 is an enlarged section taken on the line 2--2 of Fig. 1:

Fig. 3 is an enlarged section taken on the line 2-3 of Fig. 1: and

Fig. 4 is a fragmentary section taken on the line 4-4 of Fig. 2.

The embodiment illustrated comprises walls forming a vertical passage ill of rectangular cross section which opens at its upper end into an inlet chamber II and at its lower end into an outlet chamber 12. An inlet passage I4 is connected with one side of the chamber II, and an outlet passage I5 is connected with one side of the V chamber 12. walls are also provided forming an inlet chamber l1 beneath the outlet chamber i2, and an outlet chamber 18 above the inlet chamber i I. An inlet passage I! is connected with the inlet chamber I1, and an outlet passage 20 is connected with the outlet chamber I8. The inlet chambr I1 is separated from the outlet chamber 2 l2 by a horizontal plate 22 which is provided with a plurality of rows of holes to receive the lower ends of short vertical tubes 23. The outlet chamber Is is separated from the inlet chamber Ii by a horizontal plate 24 which is provided with a plurality of rows of holes to receive the upper ends of short vertical tubes 25. The tubes 2 extend downwardly from the tube plate 24 substantially across the inlet chamber II to its lunction with the passage II. Similarly, the tubes 22 extend upwardly from the tube plate 22 substantially across the outlet chamber I2 to' its Junction with the passage 10. As shown in Fig. 3, the tubes 22 in adjacent rows are aligned, and the rows extend parallel with the walls of the passage i0.

Within the vertical passage ill there are provided a plurality of rows of long vertical tubes 21 with the rows parallel with the passage walls and the tubes in adjacent rows staggered, there bein twice as many of the tubes 21 as there are tubes 22 or 25. The tubes 21 are somewhat smaller in diameter than the tubes 22 and 25. Each tube 23 is connected to the lowervends of two of the tubes 21 by means of a bifurcated fitting 29, and each tube 25 is connected to the upper ends or two of the tubes 21 by means of a similar bifurcated fitting 30. As best shown in Fig. 2, these fittings are spaced from one another to provide ample room for the flow of fluid therebetween.

It will now be apparent that the invention may be used for various purposes which require a transfer of heat from one fluid to another. For

vexample, the construction illustrated is particularly adapted for utilizing the flue gases from a steam boiler to preheat the air required for combustion of the fuel. In such use the flue gases will travel through the passage 19 and chamber i1, thence upwardly through the tubes 23, fittings 29, tubes 21, fittings II, and tubes 25 to the chamber I8 and outlet passage 20. The air will travel through the passage II and chamber ii, thence downwardly through the passage in in contact with the outer surfaces of the tubes 21, and then through the chamber l2 and outlet passage ii.

In entering the inlet chamber I i from the passage ll, and in leaving the outlet chamber 12 through the passage 15, the air will flow in directions transverse to the large tubes 25 and 23 respectively. Because oi the relatively wide spacing of these tubes 23 and 25, and their arrangement in aligned rows, the air may flow freely among them and it will be distributed very uniformly throughout the passage ill, with negligibleloss of drait at the entrance and exit ends ct this pasthe tubes 21, an intimate contact will be obtained between the air and these tubes, the air velocity in the passage will be high, a very efllcient transfer or heat will take place, and the space occupied by the apparatus will be considerably reduced.

The tubes 25 at the cold end of the apparatus are more likely than the other tubes to be corroded by reason of moisture condensing from the flue gases. Since these tubes are short as compared with the tubes 21, they can be replaced at small expense when necessary. Furthermore, if desired they can be made 01' non-corroding metal at slight additional cost.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A heat exchanger comprising walls forming two chambers connected by a passage, means to supply fluid to one side of one chamber and to withdraw the said fluid from one side of the other chamber, a group 01' tending longitudinally within the passage, a group of relatively large tubes located in one of the chambers and extending substantially across the same in the direction of the passage, a plurality of fittings each of which connects one of the large tubes to a plurality of the small tubes, the fittings being spaced from one another to provide ample room for the flow oi the said fluid therebetween, and means to supply a second fluid. for flow through the two groups 01' tubes in series to effect a transfer of heat from one fluid to the other.

2. A heat exchanser comprising walls forming relatively small tubes ex two chambers connected by a passage. means to supply fluid to one side oi one chamber and to withdraw the said fluid from one side 01' the other chamber, a group of relatively small tubes extending longitudinally within the passage, two groups of relatively large tubes located in the respective chambers andextending substantially across the same in the direction of the passage, a plurality oi flttings each of which connects one of the large tubes to a plurality of the small tubes, the fittings being spaced from one another to provide ample room for the flow of the said fluid therebetween, and means to supply a second fluid for series flow through one group 01' large tubes. the group 01' small tubes, and the other group 01' large tubes to eflect a transfer of heat from one fluid to the other.

JAMES A. BALMER.

REFERENCES CITED The following references are 01 record in the filed this patent;

UNITED STATES PA'rEN'rs 

